cloudstack.rb: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/ruby/vendor_ruby/fog/bin/cloudstack.rb - from package: ruby-fog

You may install the required package with command apt-get install {package}

Error in other languages:
cloudstack.rb: bevel nie gevind nie
cloudstack.rb: comandă negăsită
cloudstack.rb: comando não encontrado
cloudstack.rb: commande introuvable
cloudstack.rb: command not found
cloudstack.rb: käsku ei ole
cloudstack.rb: không tìm thấy lệnh
cloudstack.rb: komanda nerasta
cloudstack.rb: Kommando nicht gefunden.
cloudstack.rb: kommandot finns inte
cloudstack.rb: komut yok
cloudstack.rb: nie znaleziono polecenia
cloudstack.rb: níor aimsíodh an t-ordú
cloudstack.rb: no se encontró la orden
cloudstack.rb: no s'ha trobat l'ordre
cloudstack.rb: opdracht niet gevonden
cloudstack.rb: parancs nem található
cloudstack.rb: perintah tidak ditemukan
cloudstack.rb: príkaz nenájdený
cloudstack.rb: příkaz nenalezen
cloudstack.rb: команда не найдена
cloudstack.rb: командата не е открита
cloudstack.rb: 命令找不到
cloudstack.rb: コマンドが見つかりません